//
//  WelcomeViewController.swift
//  我的微博
//
//  Created by 李献红 on 15/10/12.
//  Copyright © 2015年 cn.lixianhong. All rights reserved.
//

import UIKit
import SDWebImage
class WelcomeViewController: UIViewController {

    /// 图像底边约束
    private var iconBottomCons: NSLayoutConstraint?
    
       override func viewDidLoad() {
        super.viewDidLoad()
        
        prepareUI()
        
        //TODO:UserAccount 为nil,不能执行sharedAccount，走到这里就崩了
        if let urlString = UserAccount.sharedAccount?.avatar_large {
         
            // 更新图像，会自动更新imageView的大小
            iconView.sd_setImageWithURL(NSURL(string: urlString))
        }
    }

    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        
        // 提示：修改约束不会立即生效，添加了一个标记，统一由自动布局系统更新约束
        //iconBottomCons?.constant  偏移量
//        iconBottomCons?.constant = UIScreen.mainScreen().bounds.height - (iconBottomCons?.constant)!
        print(iconBottomCons!.constant)
        
        iconBottomCons?.constant = -UIScreen.mainScreen().bounds.height - iconBottomCons!.constant
        print(iconBottomCons?.constant)
        
        //动画
        UIView.animateWithDuration(1.2, delay: 0.0, usingSpringWithDamping: 0.8, initialSpringVelocity: 5.0, options: UIViewAnimationOptions(rawValue: 0), animations: { () -> Void in
            //强制更新约束
            self.view.layoutIfNeeded()
            }) { (_) -> Void in
                
                //发送通知切换控制器
                NSNotificationCenter.defaultCenter().postNotificationName(BJRootViewControllerSwitchNotification, object: false)

        }
    }
    
    
     /// 准备界面
    private func prepareUI(){
    
        view.addSubview(backImageView)
        view.addSubview(iconView)
        view.addSubview(label)
        
        //自动布局
        //1>背景图片
        backImageView.ff_Fill(view)
    
        
        //2>头像
        //记录底边约束
        let cons = iconView.ff_AlignInner(type: ff_AlignType.BottomCenter, referView: view, size: CGSize(width: 90, height: 90), offset: CGPoint(x: 0, y: -160))
        //记录底边约束
        iconBottomCons = iconView.ff_Constraint(cons, attribute: NSLayoutAttribute.Bottom)
        
        //3>label

        label.ff_AlignVertical(type: ff_AlignType.BottomCenter, referView: iconView, size: nil, offset: CGPoint(x: 0, y: 16))
     

    }
    

    //MARK: - 懒加载控件
     /// 背景图片
    private lazy var backImageView: UIImageView = UIImageView(image: UIImage(named: "ad_background"))
    
    /// 用户头像
    private lazy var iconView: UIImageView = {
    
        let iv = UIImageView(image: UIImage(named: "avatar_default_big"))
        iv.layer.masksToBounds = true
        iv.layer.cornerRadius = 42
        return iv
        
    }()
    
    /// 消息文字
    private lazy var label: UILabel = {

        let label = UILabel()
        label.text = "欢迎回来"
        label.sizeToFit()
        
        return label
        
    }()
    

}
